Injection molding flow control apparatus and method

Apparatus for measuring the temperature of a nozzle having fluid material injected from an injection molding machine through a flow channel in a heated manifold that is coupled to a nozzle that is coupled to the cavity of a mold, the apparatus comprising:

• a heating device comprising a controllably heatable thermally conductive heating element;
• the nozzle comprising a tube of thermally conductive material having an outer surface and an inner surface defining a central flow bore having an axis extending from an upstream end to a downstream end of the flow bore, the flow bore being coupled to the flow channel of the manifold and the cavity of the mold;
• the heating element of the heating device being mounted on or around the outer surface of the tube of the nozzle such that heat is transferable between the heating element and the outer surface of the thermally conductive nozzle, the heating element extending along the axis of the flow bore of the nozzle to an end point of the heating element;
• a temperature monitor comprising a temperature sensor mounted on or around the nozzle at a selected position along the axis of the bore of the nozzle;
• a thermal insulator disposed along the axis of the nozzle separating the end point of the heating element and the temperature sensor;
• the heating device and the temperature monitor are mounted around an outside surface of a heating tube;
• the heating tube being comprised of a tubular wall of thermally conductive material that forms an interior mounting bore having a configuration that readily receives the outer surface of the nozzle and is readily removable from the outer surface of the nozzle, and,
• the heating device and the temperature sensor are mounted within a sheath of a thermally conductive material that is attachably cast onto and around an outside surface of the tubular wall of the heating tube.

Apparatus for measuring the temperature of a nozzle having fluid material injected from an injection molding machine through a flow channel in a heated manifold that is coupled to a nozzle that is coupled to the cavity of a mold, the apparatus comprising:

• a heating device comprising a controllably heatable thermally conductive heating element;
• the nozzle comprising a tube of thermally conductive material having an outer surface and an inner surface defining a central flow bore having an axis extending from an upstream end to a downstream end of the flow bore, the flow bore being coupled to the flow channel of the manifold and the cavity of the mold;
• the heating element of the heating device being mounted on or around the outer surface of the tube of the nozzle such that heat is transferable between the heating element and the outer surface of the thermally conductive nozzle, the heating element extending along the axis of the flow bore of the nozzle to an end point of the heating element;
• a temperature monitor comprising a temperature sensor mounted on or around the nozzle at a selected position along the axis of the bore of the nozzle;
• a thermal insulator disposed along the axis of the nozzle separating the end point of the heating element and the temperature sensor;
• the heating device and the temperature sensor are mounted within a sheath of a thermally conductive material that is attachably cast onto and around the outside surface of the nozzle.

Apparatus for measuring the temperature of a nozzle having fluid material injected from an injection molding machine through a flow channel in a heated manifold that is coupled to a nozzle that is coupled to the cavity of a mold, the apparatus comprising:

• a heating device comprising a controllably heatable thermally conductive heating element;
• the nozzle comprising a tube of thermally conductive material having an outer surface and an inner surface defining a central flow bore having an axis extending from an upstream end to a downstream end of the flow bore, the flow bore being coupled to the flow channel of the manifold and the cavity of the mold;
• the heating element of the heating device being mounted on or around the outer surface of the tube of the nozzle such that heat is transferable between the heating element and the outer surface of the thermally conductive nozzle, the heating element extending along the axis of the flow bore of the nozzle to an end point of the heating element;
• a temperature monitor comprising a temperature sensor mounted on or around the nozzle at a selected position along the axis of the bore of the nozzle;
• a thermal insulator disposed along the axis of the nozzle separating the end point of the heating element and the temperature sensor;
• the heating element is disposed within a first elongated tube comprising a thin-walled sheath, an interior bore and having a length,
• the temperature sensor is disposed within a second elongated tube comprising a thin-walled sheath, an interior bore and having a length,
• the thin-walled sheaths of the first and second elongated tubes being comprised of a thermally conductive material,
• the first and second elongated tubes being mounted on or around the nozzle, the heating element and the temperature monitor extending through the interior bores respectively of the first and seconds elongated tubes and separately terminating at first and second distal positions along the length of the first and second elongated tubes such that the end point of the heating element and the temperature sensor are separated axially along the axis of the bore of the nozzle by a distance of at least about 0.125 inches.

Apparatus for measuring the temperature of a nozzle having fluid material injected from an injection molding machine through a flow channel in a heated manifold that is coupled to a nozzle that is coupled to the cavity of a mold, the apparatus comprising:

• a heating device comprising a controllably heatable thermally conductive heating element;
• the nozzle comprising a tube of thermally conductive material having an outer surface and an inner surface defining a central flow bore having an axis extending from an upstream end to a downstream end of the flow bore, the flow bore being coupled to the flow channel of the manifold and the cavity of the mold;
• the heating element of the heating device being mounted on or around the outer surface of the tube of the nozzle such that heat is transferable between the heating element and the outer surface of the thermally conductive nozzle, the heating element extending along the axis of the flow bore of the nozzle to an end point of the heating element;
• a temperature monitor having a length and terminating at a distal end in a temperature sensor, the temperature monitor being mounted on or around the nozzle such that the temperature sensor is mounted at a position that is thermally isolated from the end point of the heating element;
• a thermal insulator disposed between the end point of the heating element and the temperature sensor, the thermal insulator being comprised of a material having a thermal conductivity of about 10 watts/meter-Kelvin or less;
• the temperature sensor being mounted on or around the nozzle such that the temperature sensor is spatially separated from the end point of the heating element by at least about 0.125 inches;
• the heating element and the temperature sensor are disposed within an elongated tube comprising a thin-walled sheath, an interior bore and having a length,
• the thin-walled sheath being comprised of a thermally conductive material,
• the elongated tube being mounted on or around the nozzle,
• the heating element and the temperature monitor extending through the interior bore and separately terminating at first and second distal positions along the length of the elongated tube such that the end point of the heating element and the temperature sensor are separated axially along the axis of the bore of the nozzle by a distance of at least about 0.125 inches.